Modern vehicles typically include an axle assembly having a housing and a differential assembly. The housing includes a cavity into which the differential assembly is positioned. The differential assembly is rotatably supported by the housing within the cavity. The differential assembly is mechanically coupled to the vehicle engine by a drive shaft. The differential assembly is also coupled to the vehicle drive wheels via a pair of axle shafts. The differential assembly regulates drive torque between the axle shafts, thereby permitting the shafts to rotate at different velocities as when one of the drive wheels is slipping.
Modern automotive vehicles frequently include systems, such as traction and stability control systems, that identify wheel slip conditions and responsively control the vehicle (e.g., engine, transmission, braking system) to reduce or eliminate wheel slip in certain instances. In such systems, a sensor is typically employed to sense the speed of a wheel or another component, such as the axle shaft, that has the rotational speed of the wheel.
One relatively common arrangement utilizes a Hall-effect sensor, which is mounted to the axle housing, and an exciter ring that is typically press-fit to the axle shaft. This arrangement typically employs a relatively large boss that is welded to the housing of the axle. Once the boss has been secured to the axle housing, several machining steps are required to drill and ream holes for the sensor, as well as to drill and tap a hole for the fastener that is employed to both orient the sensor and secure the sensor to the axle housing.
While such arrangements are suited for their intended purpose, they are nonetheless susceptible to improvement. For example, an arrangement that did not employ a discrete boss would be advantageous in that it would eliminate a part, eliminate the welding operation and would permit the sensor to be mounted relatively further outboard toward the brake mount flange where it would permit the sensor to mounted relatively closer to an outboard axle shaft support bearing. This latter aspect is important in that the sensor could be located to an area where the axle shaft experienced relatively less deflection. Also, an arrangement that did not employ a discrete sensor target, such as a sensor ring, would be advantageous in that it would eliminate a part.
Accordingly, a need exists for an axle assembly with a sensor mount which is smaller in size and reduces assembly time.